THOUSAND OAKS, Calif., May 5, 2003 - Amgen (NASDAQ:AMGN) the world's largest biotechnology company, has announced the two science teachers in Puerto Rico who are this year's recipients of the Amgen Award for Science Teaching Excellence. The Amgen awards honor public or private school science teachers, grades K-12, who demonstrate outstanding science teaching and have a great impact on the lives of their students. Each teacher will receive an unrestricted $5,000 award at a dinner event in May. For more information about the award please call the teachers below or the Amgen contact. The 2003 winners are:

Nominations are made by submitting a form and/or letter to Amgen describing why the teacher should be recognized for science teaching expertise. Nomination forms were published in newspapers, posted on Amgen's web site, and press releases were widely distributed.

A panel of three independent judges selected the winners. Judges based their decisions on evidence of the recipients' creativity and effectiveness in the classroom; their application and development of best practices in science education; their motivational ability; and their mastery of the subject matter and instructional skill.

2003 PUERTO RICO RECIPIENTS OF AMGEN AWARD

FOR SCIENCE TEACHING EXCELLENCE ANNOUNCED

In addition to the Puerto Rico program, the Amgen Award for Science Teaching Excellence is granted in California, Colorado, Kentucky, Rhode Island, and Washington, locations where Amgen has facilities. Amgen has conducted the awards program for teaching excellence for 12 years. This is the second year the awards have focused solely on science teaching.

Amgen is a global biotechnology company that discovers, develops, manufactures and markets important human therapeutics based on advances in cellular and molecular biology.

CONTACT: Barbara Bronson Gray, Amgen, Thousand Oaks, (805) 447-4949

EDITOR'S NOTE: An electronic version of this news release may be accessed via our web site at www.amgen.com. Visit the Corporate Center and click on Amgen News. Journalists and media representatives may sign up to receive all news releases electronically at time of announcement by filling out a short form in the Amgen News section of the web site.